Cannabis Research Denialism

August 1, 2007

MarkH over at the denialism blog justifiably dissects a mainstream media article sensationalizing a study on the effects of marijuana smoking on lung function. He then goes on to express drug-legalization denialist (see this comment as well) positions as a rebuttal to the drug-risk overstatements. To this I take exception. Most specifically the use of mainstream media hype and/or the usual scientific authors’ hyperbole making more of a study than is perhaps deserved to attempt to question a reasonable interpretation of the available scientific evidence. Also, I find a minimization technique suggesting that since the effects of marijuana withdrawal do not look like nicotine withdrawal, marijuana must only be “psychologically” addicting, not “physiologically” addicting particularly annoying. I address myself to this relatively common argument, as expressed in this instance by MarkH.
First, what in the heck is the basis for the use of “psychologically” and “physiologically” addicting? Are you a dualist who maintains that there is a “mind” or “psyche” that exists independently of the workings of the brain? I’m not. So by definition, if something is altering behavior, it is “physiological”. If one is attempting to dissociate somatic from brain symptoms, well, good luck with that. Yes there are some dissociable things but the interplay is really too involved, and the ultimate response that matter, i.e. behavior, is primarily brain in nature. Or are you one of these people that believes that many (all?) mental/behavioral disorders are due to personal choice and lack of “willpower” and that people should just snap out of it? This is what people usually mean when they say something is “psychological” and a contrast with “physiological” certainly suggests this is what one means. This is just as stupid for drug dependence as it is for major depression, ADHD and the like. MarkH commented that “physiological addiction has not been firmly established”. Really? How so? Take a little spin on PubMed for “cannabis withdrawal” or similar. The only way you can come up with an interpretation like Mark’s is by highly selective reading and denial of the literature in my view.

Second, beware of goalpost juggling related to this issue. Is your frame of reference for “addiction” is the rather dramatic phenomena of heroin withdrawal (perhaps a movie cartoon fictionalized version? not ALL heroin addicts look exactly alike in withdrawal severity) and presumably direct experience with nicotine withdrawal? The apparent severity, drama or somatic-pain-like nature of withdrawal from different drugs of abuse is not an exclusive indication of whether or not they are “physiologically addicting”. For that matter it is not even relevant to a reasonable discussion of “how addicting” because for this latter you need the behavior, i.e., continued drug taking in the context of a desire to quit, adverse consequences, etc.

Third, THC is a reasonably unique drug of abuse because it has a long halflife. Take a simplified version, say where withdrawal sets in once brain levels of drug / receptor occupancy decline. Symptoms can be alleviated by replacing this with a less effective but similarly acting drug like methadone for heroin or a limited, sustained dose like the nicotine patch (this is agonist therapy). The long halflife of THC in the body means that you have ongoing agonist therapy (low levels of drug still present, say, the next day) through an interval in which withdrawal would be observed after discontinuing nicotine or heroin. Again, the point is not the relative severity of symptoms or ecological significance for the organism. The point is that a subjective understanding of whether or not the human is “physiologically addicted” is compromised without accounting for this difference in pharmacokinetics. This time, try using “precipitated” in your search to review experimental ways around this issue.

Fourth, the “my friend Joe” argument (“My friend Joe smoked dope all day every day for 10 years and then just quit one day with no lasting symptoms” or similar), common to many legalize-it types, is just as flawed as the “one toke/injection and you are hooked for life” ReeferMadness type position. Donny and Dierker 2007 report that almost 40% of daily smokers (at least 10 / day for at least 10 years) don’t reach DSM criteria for dependence! Anthony et al 1994 (Exp Clin Psychopharm) shows us that the conditional probability for meeting dependence criteria given that you have experienced a drug at least once. Not the only way to calculate such a thing of course. But it suggests that only about 8% of cannabis smokers are dependent and, wait for it, only about 24% of heroin injectors are dependent. The relative population prevalences are much greater for cannabis (46% versus 1.5% in that sample), thus many, many more people are dependent on cannabis than on heroin. Odds are a given person knows a lot of cannabis users and next to zero heroin users. Even if one does know a lot of heroin users, the chances that person will be dependent is much greater. Finally, because most people’s assessment of “dependence” is biased for the drama as discussed above, a subjective impression of dependence is wildly off base.

Ultimately what I am trying to get at here is that the legalize-it crowd is just as prone to misusing science as is the bogey-man of the great Gov/DrugCzar/NIDA/Republican conspiracy to keep dope illegal. Reefer madness approaches are nutso. So are people that feel that chronic THC exposure is perfectly benign. So are people that believe that THC is not addicting. As someone who spends a deal of time trying to parse the actual risks of drugs of abuse scientifically, both types of misuse / ignorance of the available science are distasteful.

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18 Responses to “Cannabis Research Denialism”

It seems like you are assuming that the existence of cannabis dependence is relevant to the questions of (1) whether it is harmful and (2) whether it should be legal. I get that, at least in part, you are responding to arguments in the other direction: that cannabis does not induce dependence, and thus should be seen as less harmful. But no matter which way one comes out on the dependence issue, isn’t the question of dependence pretty much orthogonal to policy questions relating to harm?

There are plenty of drugs that do not seem to induce dependence–or at least only very rarely–such as some hallucingens, yet they can clearly be harmful. There are also drugs that definitively induce dependence–e.g., caffeine–yet are known to not be harmful if used moderately.

I’m not a member of the legalize it crowd. I believe in decriminalization of drugs, but not legalization.

I’m not sure how to address your strange dualism argument. There are distinct physiological mechanisms associated withdrawal from other substances – increased heart rate and blood pressure, hallucination, delusions, amplified pain, etc. The withdrawal from two drugs in particular, alcohol and cocaine is actually quite dangerous. With the DT, death occurs 1-5% of the time even with treatment, as much as 20% of the time without. Cocaine is similarly dangerous and people should go to treatment centers to quit.

Yes there is an endogenous cannabinoid receptor system that adjusts to THC use, grows tolerant and dependent. But what are the symptoms of cannabis withdrawal? Irritability and insomnia. Hardly the end of the world. There is a matter of degree here that is not being considered.

Come back when pot has people selling their bodies for a hit or laying around on the street begging for change like meth or heroin. Or when the withdrawal is so severe that it leads to significant morbidity and mortality. Then I’ll worry about it. In the meantime, jonesing for a joint has not yet made it to the DSM-IV, and while they may write papers about a marijuana withdrawal syndrome, its clinical relevance is considered minimal.

I’m not a member of the legalize it crowd. I believe in decriminalization of drugs, but not legalization.

I’m not sure how to address your strange dualism argument. There are distinct physiological mechanisms associated withdrawal from other substances – increased heart rate and blood pressure, hallucination, delusions, amplified pain, etc. The withdrawal from two drugs in particular, alcohol and cocaine is actually quite dangerous. With the DT, death occurs 1-5% of the time even with treatment, as much as 20% of the time without. Cocaine is similarly dangerous and people should go to treatment centers to quit.

Yes there is an endogenous cannabinoid receptor system that adjusts to THC use, grows tolerant and dependent. But what are the symptoms of cannabis withdrawal? Irritability and insomnia. Hardly the end of the world. There is a matter of degree here that is not being considered.

Come back when pot has people selling their bodies for a hit or laying around on the street begging for change like meth or heroin. Or when the withdrawal is so severe that it leads to significant morbidity and mortality. Then I’ll worry about it. In the meantime, jonesing for a joint has not yet made it to the DSM-IV, and while they may write papers about a marijuana withdrawal syndrome, its clinical relevance is considered minimal.

I don’t mean to be a pain in the ass, and I’m not trying to deny the existence of a group of people who need to seek treatment to get off pot. I suspect, however, the withdrawal from marijuana isn’t as important as just isolating them from their peers….

Physioprof: I was responding primarily to the issue of whether or not marijuana induces dependence. MarkH’s post and particularly the comment vis a vis “physiological” dependence and “has not been firmly established” reads like a standard denial of what to me is overwhelming evidence that chronic exposure to THC via cannabis consumption leads to dependence. This is clearly relevant to any query as to whether it is harmful. Whether it should be legal? I think the evidence that we have recreational psychoactive substances that produce dependence that are both legal (alc, nic, caff) and illegal suggests that dependence is not part of that discussion.

MarkH: You are the one that advanced the dualism argument about “physiological” and “psychological” dependence. What exactly does “psychological dependence” mean to you? Is insomnia “psychological”? Are affective phenomena somehow less “real”? It is apparent from your comments here that you in fact recognize my point that cannabis does indeed induce dependence. Your post and initial comment give an entirely different impression. I’m trying to point out that your rhetorical tactics in the post and the comment are similar to those you debunk to some extent elsewhere on your blog. The commenter who said essentially “see, markh’s critique of the MSM sensationalization of this one paper shows that all cannabis research is bullshit at core” shows the problem very nicely.

I am not arguing one bit with comparisons on the relative severity of the most extreme or even mean severity of heroin or alcohol or cocaine discontinuation. This is not the point regarding treatment of the underlying science. Just so long as your comparison does not include inaccurate representations of the cannabis side of the equation and likewise includes realistic and not cartoonish and most extreme examples of the withdrawal symptoms of alcohol or heroin.

Your comment here about getting dope smokers away from their peers and relative priority of acute withdrawal symptoms betrays a misunderstanding of addiction. These are relatively fixable problems. People can be “detoxed” through the acute withdrawal phase quite easily and, relatively speaking, cheaply. A matter of weeks. It is also possible to avoid the wrong friends. If this was all it took we wouldn’t have a problem with dependence, at least in the population that is motivated to quit. The trouble is relapse. Driven in most cases not by the friends that offer you a hit but by an internal motivation state to start consuming again. Craving so to speak. There are data. Any experience addiction clinician can tell you this is a major problem. What this tells us is to make sure to be looking at the right phenotype when comparing relative “risk” for dependence.

Woah. You know I think the problem here might be grammatical. Here is what I said:

Marijuana is not physiologically addictive (it doesn’t cause serious withdrawal) like cigarettes and other drugs

Now, I see how this could be interpreted as “no physiologic addiction” – and I think the parenthetical statement made this sentence seem stronger than I intended. My intent was to say the physiologic effects of marijuana withdrawal were not like cigarettes and other drugs, not that it does not exist at all. It does cause withdrawal, albeit minor. Most drugs do. You can become dependent on aspirin or NSAIDS for instance, and the rebound headaches from withdrawal can be a nightmare. People have been known to become dependent on nasal sprays. The question is of relative severity of the withdrawal.

Psychological dependence refers to behaviors of drug seeking and a desire to experience the high – I would describe craving and drug seeking as signs of psychological dependence. Physiological dependence refers to things that are less subjective. I’m sorry if you don’t like the language, that’s just the way they taught me in medschool. I suppose it suggests duality, but that is not intentional and it’s the way I still think of it. If there is better language to differentiate between symptoms such as craving and drug seeking and anxiety vs. more directly measuraable phenomena of withdrawal such as sedation, increased or decreased blood-pressure heart rate etc., pain hypersensitivity, vomiting/constipation etc., tremor, seizure and stroke, I’d like to know what it is.

But you also saidThere is not a similar physical dependence of marijuana compared to any of these drugs. Psychological dependence maybe, but physiological addiction has not been firmly established in humans or animal models.

My point is that the functions of the brain are both physical and physiological and that so called “psychological” phenomena result from the physiological and physical state of the brain. Your distinction is artificial if it is not in fact closet or subconsciously (psychological!) dualist. The question is, why do you use it and why were you trained to use it? More importantly, what is the result on your thinking and interpretation of data? To this latter I would suggest it is a minimization of health concerns that are not “directly measurable” as you put it. Surely you recognize this as a common critique of the medical profession.

As to replacement terminology- why do you require this classification scheme? Isn’t it enough to simply refer to cardiac, affective, motivation, etc symptoms? to be even more specific about blood pressure or depressed mood? Shouldn’t the physician be interested in all possible health concerns?

Most former users will tell you the same, and the physiologic effects of dependence appear to be reversible after abstinence, unlike alcohol, cocaine, tobacco etc.

really? “sedation, increased or decreased blood-pressure heart rate etc., pain hypersensitivity, vomiting/constipation etc., tremor, seizure and stroke” don’t remit with long term abstinence from alcohol, cocaine and tobacco? come on. this is not even remotely defensible. The most lasting and consistent “problem” associated with drug discontinuation is the prepotent urge to resume retaking drug. period. essentially permanent experience of the “directly observable” symptoms you list are comparatively much much rarer if they exist at all. Does you local AA meeting feature a bunch of folks bitching about how they just can’t stand that elevated blood pressure or living on the verge of seizure every day? heck no, they talk about the urge to drink.

drugmonkey I am certainly part of the legalize it crowd, not just cannabis but basically everything. But nonetheless i agree with what you have said. The distinction people make between psychological addiction and physical addiction has always annoyed me too. Certainly a heavy marijuana user is not going to feel very well if they stop abruptly. I have smoked for most of my adult life sometimes heavily especially when i was younger and my own experience is that stopping disturbs my sleep cycle and my eating habits. basically I sleep less and eat more when abstaining not to mention other effects like nervousness. (Oddly enough I don’t eat as much or as often when stoned, the “munchies” is something I don’t understand) This probably isn’t helped by the fact I will increase caffeine usage when I don’t have pot because to me the effects of caffeine feel much like marijuana in some ways. So I have never claimed MJ had no addictive potential but I know many do and I have argued the fact unsuccessfully i might add. People will think what they wanna think and few care about science or rationality. I also feel people often overstate marijuana’s potential medical use. Undeniably it has some but overstating its case doesn’t help the legalize it movement at all. Anyway ya have an interesting blog here and given time I plan on reading it all. peace.

all right guys…..here is my view. i am for one a part of the legalize it group. However I think the real question her is…is this something that would ruin the foundation of humanity as we know it? I think that this is the question to be asked. Whether or not it is legalized and why is totally besides the point…what are the pros and cons of both options.

It’s hard to say which quit smoking marijuana porgrams out that actually have %100 success rate. I think most people just quit pot when they reach the point where they are sick and tired of letting it control their lives. When you’ve had just about enough, you will generally find the strength within yourself to quit weed.

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[…] comes to addiction, no matter how much people wish to frame it as such. Drug Addiction Dualism is a denialist position. Full stop. Dependence on a drug is produced because repeated exposure to that drug produces […]